Nitrogen fertilizer and soybean yield: what we learned from multi-year trials in Illinois

With high yield potential and with seed high in protein (38–40%), the soybean crop requires a lot of N—roughly 4.5 lb of N per bushel, with about 3.5 lb of that removed with the grain. A 60-bushel soybean crop (similar to the current Illinois average) would need approximately 270 lb of N per acre, while an 80-bushel crop, which is not uncommon today, needs to accumulate about 360 lb of N…